A large, real-world study suggests that semaglutide’s cardiovascular effects may be more closely related to the patient’s dose than to the amount of weight loss a patient receives, providing new insight into how semaglutide protects heart health.
Study: Cardiovascular outcomes of semaglutide correspond more closely to the dose achieved than to the weight loss achieved. Image credit: KaterynaBorodina/Shutterstock.com
The amount of semaglutide administered may be more important than the amount of weight loss in patients’ long-term heart health, according to a new retrospective study published in . npj cardiovascular health.
Real-world data investigating the cardiovascular effects of semaglutide
Obesity, characterized by excessive fat accumulation in the body, is a major risk factor for cardiovascular disease and related mortality. Glucagon-like peptide-1 (GLP-1) receptor agonists, including semaglutide, have shown great promise in reducing weight, improving glycemic control, and providing cardiometabolic benefits.
These diverse therapeutic effects of semaglutide raise important mechanistic questions, namely whether these effects are aligned along a single axis or whether the drug provides separable cardiovascular effects independent of the magnitude of weight loss achieved.
Weight loss with semaglutide does not depend solely on the dose of the drug. Several factors can contribute to the final treatment outcome, including treatment adherence, tolerability, metabolic profile, and the patient’s preexisting health conditions.
Given this multifactorial involvement and the fact that weight loss represents a complex physiological response, researchers at nference, a US-based health technology company, hypothesized that weight loss and cardiovascular protection with semaglutide are not necessarily correlated responses, and that the magnitude of weight loss may not predict cardiovascular outcomes.
To investigate this hypothesis, researchers analyzed longitudinal clinical data from the federated de-identified US Electronic Health Records Network, consisting of 47,199 patients with at least one documented baseline cardiovascular disease who started semaglutide.
total 12,519 patients met inclusion criteria for the primary dose analysis, and clinical data on dose escalation and weight change during the first 2 years after semaglutide initiation were evaluated in relation to cardiovascular outcomes during the subsequent 2 years.
Higher semaglutide doses are associated with improved cardiac outcomes
The analysis showed that patients who received higher doses of semaglutide lost more weight during the first two years of treatment, with an additional 3.15% weight loss for each 1-mg increase in dose.
More importantly, patients who reached a higher maximum dose of semaglutide (≥1.7 mg) during this period had a significantly lower risk of all-cause mortality, combined cardiovascular events, cerebrovascular disease, and heart failure over the subsequent 2 years compared to patients whose maximum dose remained between 0.25 mg and 1.0 mg.
The researchers then investigated whether these cardiovascular benefits were explained by the amount of weight loss in patients. Greater maximum weight loss achieved during the first 2 years was strongly associated with better glycemic control and lower blood pressure during subsequent follow-up, but was not significantly associated with all-cause mortality or lower risk of composite cardiovascular events. These findings suggest that the cardiovascular benefits observed in this study are more closely related to the achieved dose of semaglutide than to weight loss alone.
To place these findings in a broader clinical context, the researchers also compared semaglutide to other commonly prescribed antidiabetic drugs. Propensity-matched analysis showed that semaglutide treatment was associated with lower rates of several cardiovascular disease outcomes than treatment with metformin, dipeptidyl peptidase-4 (DPP-4) inhibitors, and sodium-glucose cotransporter 2 (SGLT2) inhibitors.
Because the achieved dose of semaglutide appeared to more closely match cardiovascular disease outcomes than the maximum achieved weight loss, the researchers investigated whether the drug could have a direct effect on the heart. Analysis of whole-body single-cell atlases and publicly available transcriptome datasets revealed relatively high GLP1R transcript expression in cardiac tissue, particularly in cardiomyocytes and cardiac endothelial cells. Although these findings provide biological plausibility for a direct cardiac mechanism, they do not demonstrate functional receptor activity or support that semaglutide acts directly on these cells.
Heart benefits may extend beyond weight loss
The findings suggest that the cardiovascular benefits associated with semaglutide may not be fully explained by the weight patients lose while taking the drug. Rather, the results indicate that therapeutic exposure, reflected in the maximum dose achieved by patients, may better capture the mechanisms underlying long-term cardiovascular protection.
These observations support the growing evidence that semaglutide’s effects extend beyond weight management and glycemic control, while also highlighting that weight loss alone may not be a suitable surrogate for predicting cardiovascular benefit. However, because this was a retrospective observational study, the findings cannot prove that increasing the dose of semaglutide directly caused improved cardiovascular outcomes, and unmeasured confounders may have influenced the observed association.
Future studies will examine the cardiac mechanism of semaglutide
The findings raise the possibility that semaglutide’s cardiovascular benefits extend beyond its effects on weight loss, but the authors stress that the underlying mechanisms remain unclear. They suggest that future studies should investigate how cumulative drug exposure, peak drug concentration, and treatment compliance contribute to cardiovascular protection, and whether GLP-1 signaling in the heart and epicardial adipose tissue plays a direct role.
This study has some limitations. As a retrospective analysis of electronic medical records, it is susceptible to selection and ascertainment bias, and cardiovascular conditions and outcomes were primarily identified using ICD diagnosis codes, which do not necessarily reflect expert-confirmed diagnoses. Additionally, all participants had at least one documented cardiovascular disease at baseline, limiting the generalizability of the findings to patients without pre-existing cardiovascular disease.
The researchers also did not directly account for treatment duration or adherence, which are known to influence long-term outcomes. Additionally, laboratory and physiological measurements such as weight, hemoglobin A1c, and blood pressure were only available for some patients, which may have influenced some analyses. Prospective studies will be needed to determine whether the observed associations reflect a direct effect of semaglutide exposure or other factors related to treatment patterns and patient characteristics.
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